Getting per-resource alarm notifications with Amazon CloudWatch

This article explains how to receive per-resource alarm notifications from CloudWatch Metrics Insights alarms using native alarm actions and EventBridge Contributor State Change events for enhanced custom routing and enrichment.

• CloudWatch Metrics Insights alarms with GROUP BY evaluate each dimension combination independently and emit separate notifications per breaching resource
• Native alarm actions (SNS, Lambda) deliver per-contributor notifications automatically with no additional setup required
• EventBridge Contributor State Change events provide structured, event-driven format for custom processing and multi-destination routing
• Lambda functions can enrich notifications with contextual data, custom formatting, and conditional routing based on resource attributes
• Solution architecture includes EventBridge rules capturing events, Lambda for enrichment, and SNS or third-party integrations for delivery
• Walkthrough covers creating Metrics Insights alarms, configuring EventBridge rules, deploying Lambda functions, and testing with simulated CPU load
• Cost scales with contributor cardinality; 1,000 contributors breaching daily generates ~30,000 Lambda invocations and SNS publishes monthly

This approach ensures on-call teams receive individual notifications for each resource breach, enabling faster incident response and complete visibility across multi-account, multi-region deployments.